<title>挖地雷</title><link href="http://hzoi.com/tomorrow.css" rel="stylesheet"><div class="ui existing segment"><pre><code><span class="pl-cp">#include</span><span class="pl-cpf">&lt;cstdio&gt;</span><span class="pl-cp"></span>
<span class="pl-k">struct</span> <span class="pl-n">Edge</span><span class="pl-p">{</span>
    <span class="pl-kt">int</span> <span class="pl-n">from</span><span class="pl-p">,</span><span class="pl-n">to</span><span class="pl-p">,</span><span class="pl-n">next</span><span class="pl-p">;</span>
<span class="pl-p">}</span> <span class="pl-n">edge</span><span class="pl-p">[</span><span class="pl-mi">40005</span><span class="pl-p">];</span>
<span class="pl-kt">int</span> <span class="pl-n">head</span><span class="pl-p">[</span><span class="pl-mi">205</span><span class="pl-p">],</span><span class="pl-n">cnt</span><span class="pl-p">;</span>
<span class="pl-kt">void</span> <span class="pl-nf">add</span><span class="pl-p">(</span><span class="pl-kt">int</span> <span class="pl-n">x</span><span class="pl-p">,</span><span class="pl-kt">int</span> <span class="pl-n">y</span><span class="pl-p">){</span>
    <span class="pl-n">edge</span><span class="pl-p">[</span><span class="pl-o">++</span><span class="pl-n">cnt</span><span class="pl-p">].</span><span class="pl-n">next</span><span class="pl-o">=</span><span class="pl-n">head</span><span class="pl-p">[</span><span class="pl-n">y</span><span class="pl-p">];</span>
    <span class="pl-n">edge</span><span class="pl-p">[</span><span class="pl-n">cnt</span><span class="pl-p">].</span><span class="pl-n">from</span><span class="pl-o">=</span><span class="pl-n">x</span><span class="pl-p">;</span>
    <span class="pl-n">edge</span><span class="pl-p">[</span><span class="pl-n">cnt</span><span class="pl-p">].</span><span class="pl-n">to</span><span class="pl-o">=</span><span class="pl-n">y</span><span class="pl-p">;</span>
    <span class="pl-n">head</span><span class="pl-p">[</span><span class="pl-n">y</span><span class="pl-p">]</span><span class="pl-o">=</span><span class="pl-n">cnt</span><span class="pl-p">;</span>
<span class="pl-p">}</span>
<span class="pl-kt">int</span> <span class="pl-nf">main</span><span class="pl-p">(){</span>
    <span class="pl-kt">int</span> <span class="pl-n">n</span><span class="pl-p">,</span><span class="pl-n">x</span><span class="pl-p">,</span><span class="pl-n">y</span><span class="pl-p">;</span>
    <span class="pl-n">scanf</span><span class="pl-p">(</span><span class="pl-s">&quot;%d&quot;</span><span class="pl-p">,</span> <span class="pl-o">&amp;</span><span class="pl-n">n</span><span class="pl-p">);</span>
    <span class="pl-kt">int</span> <span class="pl-n">l</span><span class="pl-p">[</span><span class="pl-mi">205</span><span class="pl-p">];</span>
    <span class="pl-k">for</span><span class="pl-p">(</span><span class="pl-kt">int</span> <span class="pl-n">i</span><span class="pl-o">=</span><span class="pl-mi">1</span><span class="pl-p">;</span> <span class="pl-n">i</span> <span class="pl-o">&lt;=</span> <span class="pl-n">n</span><span class="pl-p">;</span> <span class="pl-n">i</span><span class="pl-o">++</span><span class="pl-p">)</span><span class="pl-n">scanf</span><span class="pl-p">(</span><span class="pl-s">&quot;%d&quot;</span><span class="pl-p">,</span><span class="pl-o">&amp;</span><span class="pl-n">l</span><span class="pl-p">[</span><span class="pl-n">i</span><span class="pl-p">]);</span>
    <span class="pl-k">while</span><span class="pl-p">(</span><span class="pl-mi">1</span><span class="pl-p">){</span>
        <span class="pl-n">scanf</span><span class="pl-p">(</span><span class="pl-s">&quot;%d%d&quot;</span><span class="pl-p">,</span><span class="pl-o">&amp;</span><span class="pl-n">x</span><span class="pl-p">,</span><span class="pl-o">&amp;</span><span class="pl-n">y</span><span class="pl-p">);</span>
        <span class="pl-k">if</span><span class="pl-p">(</span><span class="pl-o">!</span><span class="pl-n">x</span><span class="pl-o">&amp;&amp;!</span><span class="pl-n">y</span><span class="pl-p">)</span><span class="pl-k">break</span><span class="pl-p">;</span>
        <span class="pl-n">add</span><span class="pl-p">(</span><span class="pl-n">x</span><span class="pl-p">,</span><span class="pl-n">y</span><span class="pl-p">);</span>
    <span class="pl-p">}</span>
    <span class="pl-kt">int</span> <span class="pl-n">dp</span><span class="pl-p">[</span><span class="pl-mi">205</span><span class="pl-p">],</span><span class="pl-n">f</span><span class="pl-p">[</span><span class="pl-mi">205</span><span class="pl-p">],</span><span class="pl-n">maxv</span> <span class="pl-o">=</span> <span class="pl-mi">0</span><span class="pl-p">,</span> <span class="pl-n">maxi</span><span class="pl-p">;</span>
    <span class="pl-k">for</span> <span class="pl-p">(</span><span class="pl-kt">int</span> <span class="pl-n">i</span> <span class="pl-o">=</span> <span class="pl-mi">1</span><span class="pl-p">;</span> <span class="pl-n">i</span> <span class="pl-o">&lt;=</span> <span class="pl-n">n</span><span class="pl-p">;</span> <span class="pl-n">i</span><span class="pl-o">++</span><span class="pl-p">)</span> <span class="pl-p">{</span>
        <span class="pl-n">dp</span><span class="pl-p">[</span><span class="pl-n">i</span><span class="pl-p">]</span><span class="pl-o">=</span><span class="pl-n">l</span><span class="pl-p">[</span><span class="pl-n">i</span><span class="pl-p">];</span>
        <span class="pl-n">f</span><span class="pl-p">[</span><span class="pl-n">i</span><span class="pl-p">]</span> <span class="pl-o">=</span> <span class="pl-n">i</span><span class="pl-p">;</span>
        <span class="pl-k">for</span><span class="pl-p">(</span><span class="pl-kt">int</span> <span class="pl-n">x</span><span class="pl-o">=</span><span class="pl-n">head</span><span class="pl-p">[</span><span class="pl-n">i</span><span class="pl-p">];</span><span class="pl-n">x</span><span class="pl-p">;</span><span class="pl-n">x</span><span class="pl-o">=</span><span class="pl-n">edge</span><span class="pl-p">[</span><span class="pl-n">x</span><span class="pl-p">].</span><span class="pl-n">next</span><span class="pl-p">){</span>
            <span class="pl-kt">int</span> <span class="pl-n">j</span><span class="pl-o">=</span><span class="pl-n">edge</span><span class="pl-p">[</span><span class="pl-n">x</span><span class="pl-p">].</span><span class="pl-n">from</span><span class="pl-p">;</span>
            <span class="pl-k">if</span> <span class="pl-p">(</span><span class="pl-n">dp</span><span class="pl-p">[</span><span class="pl-n">j</span><span class="pl-p">]</span> <span class="pl-o">+</span> <span class="pl-n">l</span><span class="pl-p">[</span><span class="pl-n">i</span><span class="pl-p">]</span> <span class="pl-o">&gt;</span> <span class="pl-n">dp</span><span class="pl-p">[</span><span class="pl-n">i</span><span class="pl-p">])</span> <span class="pl-p">{</span>
                <span class="pl-n">dp</span><span class="pl-p">[</span><span class="pl-n">i</span><span class="pl-p">]</span> <span class="pl-o">=</span> <span class="pl-n">dp</span><span class="pl-p">[</span><span class="pl-n">j</span><span class="pl-p">]</span> <span class="pl-o">+</span> <span class="pl-n">l</span><span class="pl-p">[</span><span class="pl-n">i</span><span class="pl-p">];</span>
                <span class="pl-n">f</span><span class="pl-p">[</span><span class="pl-n">i</span><span class="pl-p">]</span> <span class="pl-o">=</span> <span class="pl-n">j</span><span class="pl-p">;</span>
            <span class="pl-p">}</span>
        <span class="pl-p">}</span>
        <span class="pl-k">if</span><span class="pl-p">(</span><span class="pl-n">dp</span><span class="pl-p">[</span><span class="pl-n">i</span><span class="pl-p">]</span><span class="pl-o">&gt;</span><span class="pl-n">maxv</span><span class="pl-p">){</span>
            <span class="pl-n">maxv</span><span class="pl-o">=</span><span class="pl-n">dp</span><span class="pl-p">[</span><span class="pl-n">i</span><span class="pl-p">];</span>
            <span class="pl-n">maxi</span><span class="pl-o">=</span><span class="pl-n">i</span><span class="pl-p">;</span>
        <span class="pl-p">}</span>
    <span class="pl-p">}</span>
    <span class="pl-kt">int</span> <span class="pl-n">top</span><span class="pl-o">=</span><span class="pl-mi">1</span><span class="pl-p">,</span><span class="pl-n">stack</span><span class="pl-p">[</span><span class="pl-mi">1005</span><span class="pl-p">];</span>
    <span class="pl-k">for</span><span class="pl-p">(;</span><span class="pl-n">f</span><span class="pl-p">[</span><span class="pl-n">maxi</span><span class="pl-p">]</span><span class="pl-o">!=</span><span class="pl-n">maxi</span><span class="pl-p">;</span><span class="pl-n">maxi</span><span class="pl-o">=</span><span class="pl-n">f</span><span class="pl-p">[</span><span class="pl-n">maxi</span><span class="pl-p">])</span><span class="pl-n">stack</span><span class="pl-p">[</span><span class="pl-n">top</span><span class="pl-o">++</span><span class="pl-p">]</span><span class="pl-o">=</span><span class="pl-n">maxi</span><span class="pl-p">;</span><span class="pl-n">stack</span><span class="pl-p">[</span><span class="pl-n">top</span><span class="pl-p">]</span><span class="pl-o">=</span><span class="pl-n">maxi</span><span class="pl-p">;</span>
    <span class="pl-k">while</span><span class="pl-p">(</span><span class="pl-n">top</span><span class="pl-p">)</span><span class="pl-n">printf</span><span class="pl-p">(</span><span class="pl-s">&quot;%d%s&quot;</span><span class="pl-p">,</span><span class="pl-n">stack</span><span class="pl-p">[</span><span class="pl-n">top</span><span class="pl-o">--</span><span class="pl-p">],(</span><span class="pl-n">top</span><span class="pl-o">!=</span><span class="pl-mi">1</span><span class="pl-o">?</span><span class="pl-s">&quot;-&quot;</span><span class="pl-o">:</span><span class="pl-s">&quot;</span><span class="pl-se">\n</span><span class="pl-s">&quot;</span><span class="pl-p">));</span>
    <span class="pl-n">printf</span><span class="pl-p">(</span><span class="pl-s">&quot;%d</span><span class="pl-se">\n</span><span class="pl-s">&quot;</span><span class="pl-p">,</span> <span class="pl-n">maxv</span><span class="pl-p">);</span>
<span class="pl-p">}</span>
</cpde></pre></div>